Musician Molemo "Jub Jub" Maarohanye lied when he described the accident in which four school children were killed and two others seriously injured in 2010, a Soweto court heard on Monday.
Maarohanye's co-accused, Themba Tshabalala, started to testify in his own defence in their murder trial in the Protea Magistrate's Court.
"After overtaking Molemo's car we drove for a few seconds and that's when the accident happened," an emotional Tshabalala said.
"I heard a knock on the right back of the car, the driver's side at the back... My car lost control, started spinning and it capsized."
Tshabalala was giving evidence led by his lawyer, Mlungiseleli Soviti.
Maarohanye, wearing blue jeans, a white shirt, purple tie and black pullover, sat in the dock listening to Tshabalala's testimony. Family members of the school children were also in court.
Soviti asked him if evidence given by Maarohanye and previous witnesses, saying that he caused the accident, was true.
"It's not true... I am certain that it's not true [that my car hit Maarohanye's car]," Tshabalala told the court.
Soviti asked Tshabalala what speed he was driving and to describe his state of sobriety.
"I was driving at 60km/h.... I was not drunk or tipsy," he replied.
Earlier, Tshabalala admitted to having a glass of whiskey, mixed with water, during lunch, but said he did not use drugs.
Tshabalala told the court the impact at the rear of his car caused him to lose control of it.
"I tried to point it to the right direction, but I was unsuccessful... I couldn't see what was happening outside."
Soviti asked if there were children walking on the side of the road, or on the road, when the accident happened. Tshabalala said there were.
"Did you see your car hit the kids?" Soviti asked.
"No, I didn't," Tshabalala replied.
"Do you deny that your car hit some of the kids?" Soviti asked.
"No, I can't deny it," Tshabalala replied, close to tears.
He said he had no intention of hitting the children or being negligent on the day.
The court heard that Tshabalala was sent to regular drug testing after his family heard reports that he was using drugs.
On May 7, eyewitness Mphumelelo Vezi, a passenger in Tshabalala's car, told the court the left rear of Tshabalala's blue Mini Cooper had hit the right rear of Maarohanye's grey Mini Cooper.
"I did not see it, but I felt it and I heard it... The bang was loud, but not very loud. I was sitting on the left rear of the blue car, where the bang was," he said at the time.
Maarohanye and Tshabalala are facing charges of murder, attempted murder and driving under the influence of alcohol and drugs.
The two were allegedly racing their Mini Coopers when they crashed into a group of school children along Mdlalose Street in Protea North on March 8, 2010. Four boys were killed and two others seriously injured.
Last week Monday, magistrate Brian Nemavhidi provisionally closed the case against Maarohanye, until an expert witness could testify in his defence.
Maarohanye's defence intended calling an IT expert to challenge the authenticity of cellphone video footage presented by the State earlier in the trial.